Buttonhole-length regulator for sewing machines



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D. G. SMITH 041914101 GSA/1TH Get. 31, 1950 BUTTONHOLE-LENGTH REGULATOR FOR SEWING MACHINES Filed Dec.

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BUTTONHOLE-LENGTH REGULATOR FOR SEWING MACHINES Filed Dec. 2, 1948 D. G. SMITH Oct. 31, 1950 4 Sheets-Sheet 3 Patented Oct. 31, 1950 I BUTTONHOLE-LENGTH REGULATOR FOR SEWING MACHINES Darwin G. Smith, Bridgeport, Conn., assignor to The Singer Manufacturing Company,.Elizabeth,- N. J .,.a corporation of New J ersey Application December 2, 1948, Serial No. 63,103

9 Claims.

This invention. relates to sewing machines and more particularly to improvements in buttonholelength regulating means for sewing machines of the type disclosed in the U. S. patent of E. B. Allen; No. 738,591, granted September 8, 1903.

In the use of buttonhole sewing machines, it is frequently necessary to change the length of the buttonhole'being produced. It is, of course, desirable. that the buttonhole machine be equipped with a suitable buttonhole length regulating means which is readily accessible to the operator, whereby the adjustments in the length of the buttonhole can be made conveniently without requiring the use of tools or the like.

In prior machines of the type illustrated in the above mentioned Allen patent, means were provided by which the length of the buttonhole could be varied. I However, in making the adjustment necessary to change the length of the buttonhole, an oil-guard had to be removed from the machine following which it was necessary to use a special Wrench to loosen a work-clampcarrier regulator stud nut. The work-clamp shifting link thus released was then manually moved to the desired position with the aid of a gauge properly placed on the bed of the machine. While this method was more or less satisfactory, it required the use of a special wrench and a gauge both of which frequently were misplaced and could not be readily located, Moreover, since no micrometer adjustment was provided on the prior machines, a trial-and-error method had to be followed in acquiring the proper setting. Since both a wrench and a gauge were necessary in making the adjustments, the changing of the buttonholev length was a time consuming operation. 7

Therefore, it is the primary object of the present invention to provide an improved means for regulating the length of the buttonhole, which means is readily accessible to the operator whereby adjustments in the length of the buttonhole can be made conveniently and without th use of any tools or gauges.

Another object of the present invention is to provide a buttonhole-length regulatingmeans which can be securely locked in its selected position of adjustment.

A further object of the present invention is to provide animproved buttonhole-length regulator which is self-contained and adaptedfor convenient application to machines already in the trade.

With. the above and other objects in view, as will hereinafter appear, the invention comprises the devices, combinations and arrangements of 2 parts hereinafter set forth and illustrated'in the accompanying drawings of a preferred embodiment of the invention, from which the several features of the invention and the advantages attained thereby will be readily understood by those skilled in the art.

The invention will best be understood by referring to the accompanying drawings, in which:

Fig. 1 is a left side elevational View, partly in section, of a buttonhole sewing machine equipped with a preferred form-of the invention.

Fig. 2 is a bottom plan View of the machine shown in Fig. l, with a portion of the feed-cam broken away to show the preferred form of buttonhole-length regulator.

Fig. 3 is a top planview of the buttonholelength regulator set to produce a buttonhole of maximum length.

Fig. 4 is a view similar to Fig. 3, but with the device set to produce a buttonhole of minimum length.

Fig, 5 is an end View of the device with the sewing machine bed in section taken substantially along the broken line 55, Fig. 2.

Fig. 6 represents a section taken substantially along the line 66, Fig. 3, showing, in full lines, the adjusting handle in retracted or out-of-theway position and, in dotted lines, the adjusting handle in operating position.

Fig. '7 represents a section taken substantially along the line 1-1, Fig. 3, illustrating the pre ferred form of clamp for locking the buttonholelength device in its selected position of adjustment.

Fig. 8 is a section taken transversely of the sewing machine bed substantially along the line 88, Fig. 2, showing the front side of the improved regulator.

Fig. 9 is a section taken transversely of the sewing machine bed substantially along the line 99, Fig. 2, showing the rear side of the regulator.

Fig. 10 is a disassembled perspective view of the buttonhole-length regulator, illustrating the details of the component parts.

Referring to the drawings, the machine chose for the purpose of the present disclosure has a frame including a bed 29 from which rises a standard 2! of the bracket-arm 22. terminating in a head 23. Journaled in the bracket-arm 22 is a belt-driven main-shaft 24 connected in the head 23 to the usual reciprocator and laterally vibratory needle-bar 25 carrying a needle 25. Complemental to the needle 26 in the formation of lock-stitches isa conventional oscillating shuttle 21 driven by a bed-shaft 28 (Fig. 2) operatively connected to the main-Shaft 24 in a manner represented in U. S. Patent No. 784,291, issued to E. B. Allen, on March '1, 1905.

The work to be buttonholed is adapted to be held in a work-clamp comprising an upper clampfoot 29 and a lower work-plate 30 mounted as usual on a longitudinal slide-plate 3| having movement lengthwise of the bed 20 in a cross slide-plate 32 which has movement transversely of the bed 20. Movements are imparted to the slide-plates 3| and 32 by a feed-cam 33 in a manner such that the work-clamp is, slowly moved in step-by-step fashion under theendwise reciprocatory and laterally vibratory needle 26, first away from the standard and then towards the standard to cause the first and second rows of side zigzag stitches to be laid side by side in the work. The feed-cam 33 is detachably secured on the lower end of a vertically disposed feedshaft 34 journaled in the bed 20 and bracket-arm 22 of the machine-frame. The feed-shaft 34 has imparted to it semi-rotational impulses through a suitable train of gears 35 (Fig. 1) actuated from the arm-shaft 24 in a manner fully disclosed and explained, for example, in the U. S. patent of E. B. Allen, No. 1,559,539, dated November 3, 1925. It will be understood that the feedcam 33 is given one revolution per buttonhole producing cycle.

The connections between the fed-cam 33 and the work-clamp for shifting the latter transversely of the needle 26 at the opposite ends of the buttonhole are shown in Fig. 2 and comprise a lever 36 fulcrumed intermediate its ends at 31. One end of the lever 36 is fitted with a roller 38 positioned to track a cam-groove 39 in the feedcam 33 and the other end of the lever 36 is adjustably secured to the cross slide-plate 32. R- tation of the feed-cam 33 will impart a rocking movement to the lever 36, causing the cross slideplate 32 to shift relative to the bed 20, resulting in a lateral shift of the work-clamp.

The connections for effecting the longitudinal shift of the work-clamp are best shown in Figs. 2 and 3 and comprise an angle-lever 46 fulcrumed for rocking movement on a pivot-stud 4| threaded into the bed 20. One arm 42 of the anglelever 40 is fitted with a roller 43 engaging a camgr-oove 44 in the feed-cam 33. The other arm 45 of the angle-lever 40 is curved and is formed with an arcuate slot 46 in which is slidably disposed a block 41 provided with a stud 48 to which is pivoted one end of a link 49. At its other end, the link 49 is connected to a stud 50 (Fig. depending from a slide-block 5| attached to the under side of the longitudinal slide-plate 3|. From the above, it will be understood that rotation of the feed-cam 33 will impart turning impulses to the angle-lever 40 about its pivot-stud 4| and that through the link 49 these impulses will be converted into longitudinal displacements of the work-clamp.

The length of the buttonhole produced or, in other words, the extent of longitudinal travel of the work-clamp depends on the position of the slide-block 41 in the arcuate slot 46 of the anglelever 40. The present invention is directed to improved means for selectively positioning the slide-block 41 in the arcuate slot 46. As best illustrated in Fig. 10, this means, which for convenience will be referred to as a buttonholelength regulator, comprises essentially a baseplate 52, linkage members 53 and 54 and an actuator or crank-member 55. The base-plate 52 4 is shown as attached to an extension 56 provided on the angle-lever 40 in a manner such that the base-plate 52 and the angle-lever 40 in efi'ect comprise a single member, referred to hereinafter as a base-member, and turn as a unit about the pivot-stud 4| of the angle-lever 40. At its free end, the extension 56 of the angle-lever 40 has pivoted to it one end of the swing-arm 54 connected at its other end to the stud 48 carried by the slide-block 41. Intermediate its ends the arm 54 has pivoted to it, by the stud 51, the ofiset end 58 of the link 53 apertured at 59 to embrace a crank-pin 60 in the form of a stud extending through a circular clearance slot 6| in the baseplate 52 and threaded into the bottom of an actuator in the form of the conical disk 55. The conical disk is freely journaled on a cylindrical projection 62 provided on the base-plate 52 and is secured for turning movement on said projection by a cap-screw 63. It will be understood that the crank-disk '55 is disposed outside of the bed 20 and that a manual turning of the crankdisk will, through the crank-pin 60, shift the link 53 substantialy endwise, causing a swinging of the arm 54 and a shift of the slide-block 41 in the arm 45 of the angle-lever 40. A movement of the slide-block 41 toward the pivot-stud 4| will result in a shortened buttonhole, while a movement in the opposite direction will result in a longer buttonhole. To assist in turning the crank-disk 55, there is provided a crank-handle 64 hinged at 65 to the crank-disk, whereby the handle can be swung from operative position, shown in dotted lines in Fig. 6, to an inoperative position, shown in full lines in the same figure, where it is substantially concealed in a transverse slot 66 formed in the top of the crank-disk 55. To facilitate shifting of the buttonhole-length regulator to the proper buttonhole size, there is scribed on the conical surface of the crank-disk 55 suitable indicia 61 complemental to a fixed pointer 68 attached to the base-plate 52. When the device is adjusted to produce the desired length of buttonhole, a suitable locking means is provided to maintain the device in proper adjustment. The locking means employed functions to clamp the link 53 firmly to the bottom of the base-plate 52 and thereby prevent relative movement between the link 53 and the baseplate 52. The locking means preferably comprises a screw 69 (Figs. 7 and 10) countersunk at 10 in the base-plate 52 and having its threaded portion extending downwardly through an arcuate clearance slot 1| in the link 53. Threaded on the screw 69 is a wing-nut 12 which when tightened securely clamps the link 53 to the bottom of the base-plate 52. To prevent the screw 69 from turning in the base-plate 52, the screw is formed beneath its head with a square portion 13 adapted to be received in one of a plurality of positions in the sixteen-sided aperture 14 (Fig. 10) in the base-plate 52. The purpose of providing the many sided aperture 14 is to permit the screw 69 to be positioned in the baseplate 52 so that the wing-nut 12 when tightened will be located beneath the crank-disk 55 where it is readily accessible to the operator. To prevent injury to the fingers of the operator when effecting a release of the wing-nut 12, there is secured on the wing-nut a horizontal guard-plate 1 5 which functions to prevent the fingers of the operator from contacting the screws (Fig. 8) which secure the pointer 68 to the base-plate 52.

From the above description taken in connection with the accompanying drawings, it will be understbou that -1 1 have devised a *buttonhole le'ngth regulator designed- -so that when itis appliedtofa ibuttonhole'sewing machine-the length-pf the -but- :t'on'hole can be readily controlled --froma l oint lo'utside theconfines of the machine-bedby merely loosening -the wing-nut -H and -turning the crank-lever-'6 i-until the desired length of buttonhole is indicated at the pointer 68. After the adjustment is nfadepati'g'hteriing-of the wing-nut 12 will lock the buttonhole-length regulator against accidental movement. It will be appreciated that the improved regulator can be easily applied to existing machines by merely removing the conventional form of angle-lever ill and substituting the present buttonhole-length regulator which is a unitary assembly. The entire change can be accomplished by using only a screw-driver. Also, it will be appreciated that the face-to-face or stacked arrangement of the base-member 52 and the link 53 contributes toward a compact device which enables the same to be applied to existing machines without in any way interfering with the operation of the parts of the machine.

Having thus set forth the nature of the invention, what I claim herein is: l

l. A buttonhole-length regulator for sewing machines having a work-clamp and means for imparting work-advancing movements to said work-clamp including a link, comprising a base member formed with a slot and adapted to be pivotally mounted on said sewing machine, means for adjustably securing saidlink insaid slot, a crank-member rotatably supported on said basemember, a swing-arm pivotally connected at one end to said base-member and at its other end connected to move said link lengthwise of saidslot, and a second link cperatively connecting said crank-member to said swing-arm.

2'. A buttonhole-length regulator for sewing machines having a work-clamp and means for imparting work-advancing movements to said work-clamp including a link, comprising a basemember formed with a slot and adapted to be pivotally mounted on said sewing machine, means for adjustably securing said link in said slot, a manually controlled crank-member rotatably supported on said base-member, a swing-arm pivotally connected at one end to said base-member and at its other end connected to shift said link lengthwise of said slot, at secondlink operatively connecting said crank-member to said swing-arm, and a locking means for securing said first link in a selected position lengthwise of said slot.

1 3. A. buittonhole-length regulator for sewing machines having a work clamp and means for imparting work-advancing movements to said work-clamp including a link, comprising a basemember formed with a slot and adapted to be pivotally mounted on said sewing machine, means for adjustably securing said link in said slot, a manually controlled crank-member rotatably supported on said base-member, a swing-arm pivotally connected at one end to said base-memher and at its other end connected to shift said link lengthwise of said slot, a second link operativel connecting said crank-member to said swing-arm, and a locking device for clamping said second link against said base-member.

4. A buttonhole-length regulator for sewing machines having a work-clamp and means for imparting work-advancing movements to said work-clamp including a link, comprising a basemember formed with a slot and adapted to be pivotally mounted on said sewing machine, means 6 ;ro1- adjustably securing said link in "said slot, a cra nk-member rotatably supported on saidbasemember, a swing-arm pivotally connected at oneend-to said base-member and atits other end 5 "connected to shift said link lengthwise of said =slo't1 a second link operatively connecting said -cr-ank-meinberto said swing-arm, and a'lock'ing detice forclamping said second ;link against said base meniber,'said -locking device including -a 10 screw and a wing-nut threaded on said screw.

5. A buttonhole-length regulator for sewing machines having a work-clamp and means for imparting work-advancing movements to said work-clamp including a link, comprising a basemember formed with a slot and adapted to be pivotally mounted on said sewing machine, means for slidably supporting said link in said slot, a swing-arm fulcrumed on said base-member and connected to shift said link lengthwise of said slot, a second link operatively connected to said swing-arm, acrank-member rotatably mounted on said base-member and operatively connected to said second-link, and indicia providing for indicating the position of adjustment of said crankmember. 6. A buttonhole-length regulator for sewing machines having a work-clamp and means for imparting work-advancing movements tosaid work-clamp, including a link, comprising a, basemernber formed with a slot and adapted to be pivotally mounted on said sewing machine, means for slidably supporting said link in said slot, a swing-arm fulcrumed on said base-member and connected to shift said link lengthwise of said slot, a second link operatively connected to said swing-arm, a crank-disk rotatably mounted on said base-member, a crank-pin provided on said crank-disk and operatively connected to said second link, and indicating means providing for facilitating adjustment of the buttonhole-length regulator, said indicating means including indicia on said crank-disk and a cooperating pointer fixed on said base-member.

'7. A buttonhole-length regulator for sewing machines having a work-clamp and means for imparting work-advancing movements to said work-clamp including a link, comprising a basemember formed with a slot and adapted to be pivotally mounted on said sewing machine, means for slidably supporting said link in said slot, a swing-arm fulcrumed on said base-member and connected to shift said link lengthwise of said slot, a second link operatively connected to said swing-arm, a crank-member rotatably mounted on said base-member and operatively connected to said second link, a crank-handle having an operative position and a retracted position, and means connecting said crank-handle to said crank-member.

8. A buttonhole length regulating device adapted for use on sewing machines having a work-clamp and means for imparting work-ad vancing movements to said work-clamp including a link, comprising a base-member having a, slot,

7 in said base-member and projecting through said means shiftably supporting said link for moveclearance slot in said second link, and a wing-nut threaded on said screw for clamping said second link to said base-member.

9. A buttonhole sewing machine having a work-clamp, means for imparting traveling movements to said work-clamp including a cam, a

=pivota11y mounted lever operatively connected to said cam and having a slot formed therein, a

vlink, means shiftably supporting said link for movement endwise of said slot, a swing-arm fulcrumed on said lever and connected to shift said link endwise of said slot, a second link operatively connected to said swing-arm, and a manually controlled actuator mounted on said lever and connected to operate said second link.

DARWIN G. SMITH.

No references cited. 

